Process of utilizing the metalloids in crude iron for reducing metallic iron.



ARD.

' H. D. PROCESS OF UTILIZING THE LLOIDS IN CRUDE IRON FOR REDUCING METALLIC I APPLICATION FILED MAR. 23.

' WITNESSES INVENTOR ATTORNEYS PATENTED APR. 21, 1908.

. UNITED STATES PATENT OFFICE.

HENRY D. HIBBARD, OF PLAINFIELD, NEW JERSEY.

PROCESS OF UTILIZILIG- THE METALLOIDS IN CRUDE IR ON FOR REDUCING METALLIC IRON.

Specification of Letters Patent.

Patented April 21, 1908.

To all whom it may concern:

Be it known that I, HENRY D. HIBBARD, a citizen of the United States of America, residing in the city of Plainfield, Union county, and State of New Jersey, have invented a Process of Utilizing the Metalloids in Crude Iron for Reducing Metallic Iron, of which the may result either (1) in refining only, that is, 2

securing the elimination of silicon and manganese, or (2) in puriiying, as well as refining the iron, that is, eliminating hosphorus and sulfur, as well as silicon an manganese, or

' (3) in partial decarbonization of the iron, as

well as refining or purifying, or both.

The effect of carrying out my process is to secure a great saving in the time required for makin a charge of steel, as well as securing gain 0 iron as it gives increased yield from energy, which, in present practice, largely goes to waste. these results, viz., the saving of time and gain in yield, have an important effect in reducing the cost of steel manufacture.

The important feature of my invention consists in charging a vessel with a quantity of molten crude iron and oxid of iron, the

' crude iron containing suflicient of the metalsufficient heat to kee loids to give by their oxidation heat enough to reduce a sufficient amount of oxid of iron to supply the necessary oxygen and maintain t e charge in a molten condition during the treatment, and mechanically agitating this charge in the vessel without the introduction of fuel other than the metalloids in the iron. The reaction between the metalloids of the crude iron and the oxid of iron will burn the metalloids which will generate the mixture molten, as Well asto reduce t e chemical equivalent of iron from its oxid and to form the slag, and this without the addition of fuel or heat to the vessel beyond that added in the two It will be understood that- .and discharging. The vessel is the heat of t e interior in edients. With some varieties of iron sufficiently high in silicon, the oxid of iron may be added cold. If the silicon in the iron be low in amount, the oxid of iron is preferably put into the vessel in a molten condition, but with a greater percenta e of silicon in the crude iron, the oxid added may be heated, or, as I have said, may in some caseseven be cold, but it should be dry. To keep up the heat ofthe operation, I select iron containing sufficient amounts of silicon (and in the basic process, phosphorus) to give by their comustion the necessary temperature.

The quantity of ore or other oxid of iron added is roportioned to the amount of crude iron' use and the amount of decarbonization desired in the product. I may add only enough oxid of iron to the charge to burn the silicon and manganese, and in some cases the phosphorus, or I may add more to burn a art of the carbon. Enough carbon is ke t in to lower the fusion point of theiron to t e proper degree in order to keep the refined metal liquid at the temperature of the process.

I'may carry out my rocess by means of various constructions o a paratus, but for the more ready understan ing of my invention I have illustrated in the sectional view,

in the accompanying drawing, a vessel whichmay conveniently be employed for the purose, and the use of which will be described y way of example only.

The vessel illustrated in the drawing is arranged so as to oscillate upon an axis at A, and it has two pockets P, I on opposite sides of this axis, each pocket large enough tohold practically all the charge and having a di- -viding partition p between them. The side walls may be extended u wardly and inwardly so as to provide a substantially closed vessel,'leaving only an opening for charging referably designed to conserve as much as possible. The charge introduced into the vessel is mixed by oscillating the vessel back and forth upon its axis so that.

the molten charge is poured over the dividing partition wholly or in a large art at each oscillation, the lighter oxid on t e top going first and the heavier metal then passing through it.

This re eated curing of the heavier metal throug the lig ter oxid is an charge.

' the essential important feature of the process. The vessuitable blast; this simply to get the process started under suitable conditions of heat, but in the process itself I rely wholly on the heat of oxidation furnished by the metalloids. When the vessel has-thus been suitably heated, I introduce the oxid either molten or heated or cold, as I have before explained, and I run in the molten crude iron of the The order of introducing the crude iron and the oxid may be reversed, if desired, by adding the iron first. I may add some lime to the charge to form a part of the base needed for the slag to favor dephosphorization of the iron.

The vessel may have either an acid lining, or a basic lining, depending upon the composition of the crude iron and upon the subsequent treatment to be given the refined iron, that is, whether it is to be made into steel by an acid or basic rocess. If the purpose is to utilize the metal oids with the view of refining merely, that is elimination of silicon and manganese, the vessel should have an acid lining with the formationof a uni-silicate slag. If there is to be a purifying of the iron by the elimination of phosphorus and sulfur, as well as refining by the elimination of silicon and manganese, the vessel should have a basic lining and a tri-silicate slag will be formed, if the purification is to be complete. If there is to be a partial decarbonization as well, the vessel should be acid or neutral lined, if there is no intention to eliminate the phosphorus,

but basic lined if phosphorus is to be eliminated.

In all other processes in which an elimination of the metalloids from crude iron occurs, object has been the conversion of the iron into steel, and while in some cases there has been incidental and incom lete utilization of the potential energy of t e metalloids, the gain of iron, when it has occurred, has'been of secondary importance. In the present process, however, since the product 1s merely to serve as a raw material for steel making processes, exact composition is not a requisite in the product, and the rocess may be carried out on such lines an under such conditions as will give the largest percentage of gain andthe largest output due to the greatest economy of time and heat. The best practice requires that the loss of both heat and time must be kept. at a minimum.

As will be understood from the foregoing explanations, the process is based on the that this may be more t utilization of the excess of heat of combustion of the metalloids, lparticularly silicon and phos horus over t at of iron. This excess is w lolly relied on to furnish the necessary heat to carry out the rocess. In order oroughly understood, I will now give figures as to proportions and calorific powers in the caseof a treatment in an acid or neutral lined vessel for a refining process resulting in the elimination of silicon and manganese, but it will be understood that these figures are given merely by Way of exam le. The reaction is quite rapid, so that with the charge sugested in the example ten minutes will sufiice for the treatment.

Taking the following grade of iron by way of example:

3Si=2.00% heat of combustion =7830 C. Mn= .50% heat of combustion to Mn,O -=24i0 C.

P= 50% S= 04% 051.00% eat of combustion to CO 8080 C.

heat of combustion to CO =2473 C. Fe=92 {heat of combustion to Fe O4=1G48 C. 0 heat of combustion to F6103=1746 G.

These two metalloids when oxidized will generate heat as follows Si 200 X 7830=1. 560. 000 calories Mn 50 X 24l0== 120. 500calories Total. .1. 686. 500 calories.

Assume inthis case that no carbon is oxidized. The 242.5 kilos of oxygen re uired would be combined with about 636 in os of iron in the form of magnetic oxid (878 kilos) considering that the oxygen is 27.6% of the weight. The heat re uired to dissociate this amount of magnetic oxid (Fe O,) would be 636 1648 1048.128 calories.

, If Fe,,( be the source of the oxygen, it will require 807 kilos, containing 565 kilos of iron. To dissociate this will'require 565 X1746 986490 calories.

The gain of iron in this case is 6.36 per cent. For forming the-slag 200 kilos Si forms 428 kilos SiO and 943 kilos SiO FeO, 50 kilos Mn forms 72 kilos M nO The Mn,,O re laces FeO in the slag.

or complete refining (desiliconization) then there must be added 878% kilos Fe o,

(magnetic oxid) to suplp'lyoxygen and about 443 kilos to form V s kilos magnetic oxid of iron (perhaps partly replaced by lime) equal to 132 kilos per metric' ton of iron treated, which must be heated to the melting point of the refined iron or say 1400 C. Assuming the specific heat of these oxide to average .20, the amount of heat required to raise their tem erature to 1400 (3., starting with them col would be 1321 x 1400 .20'= 369880 calories.

The heat required then is For heating and fusing the oxide 369880 calories For dissociation of the oxid of iron. .1048128 calories Total 141so0s calories The heat available is .1686500 calories Surplus 268492 calories If the oxids be added hot, say at 800 C., there would be a saving of heat of 1321 X800 X .20 211360 calories which would increase the surplus heat to 268492 211360 479852 calories.

probably be a positiveamount.

I claim as my invention 1. The mode herein described of utilizing the calorific power of the metalloids in crude iron in its reduction of iron from the oxid to the metallic state, said mode consistin in charging a vessel with a quantity of .mo ten crude iron and addin thereto a quantity of oxid of iron, and mec anically a itating the mixture, the quantity of oxid 0 iron being so pro ortioned to the quantity of crude iron that t e charge is maintained in molten con dition by the oxidation of the metalloids in the crude iron without substantially affecting the carbon.

2. The mode herein described of utilizing the calorific ower of the metalloids in crude iron in its re uction of iron from the oxid to the metallic state, said mode consisting in heating the .interior of a vessel, then charging this preheated vessel with a quantity of molten crude iron and adding thereto a quantity of oxid of iron, and mechanically agitating the mixture, the guantity of oxid 0 iron being so proportione to the quantity of crude iron that the charge is maintained in molten condition by the oxidation of the metalloids in the crude iron without substantially affecting the carbon.

' 3. The mode herein described of utilizing the calorific power of the metalloids in crude iron in its reduction of iron from the oxid to the metallic state, said mode consistingin charging a vessel with a uantity of molten crude iron and adding t ereto, part at a time, a quantity of oxid of, iron, and me- I the quantity chanically agitatingthe tity of oxid of iron being'so pro ortioned to the quantity of crude iron that t e charge is maintained. in molten condition by the oxidation of the metalloids in the crude iron without substantially affecting the carbon.

4. The mode herein described of utilizing the calorific ower of the metalloids in crude iron in its re notion of iron from the oxid to the metallic state, said mode consisting in charging a vessel with a quantity of mo ten crude iron and addin thereto a quantity of oxid of iron, and mec anically agitating the mixture in the vessel while it. is substantially closed, the uantity of oxid of proportione to the quantit that the charge is maintaine in moltencondition by the oxidation of the metalloids in the crude iron without substantially affecting the carbon.

5. The mode herein described of utilizing the calorific ower of the metalloids in crude iron in its re uction of iron from the oxid to of crude iron the metallic state, said mode consistin in charging a vessel with a quantity of mo ten crude iron and addin thereto a quantity of oxid of iron, and meo anically agitating the mixture and repeatedly pouring the molten crude iron through the body of oxid of iron,

of oxid of iron being so proportioned to the quantity of crude iron that the charge is maintained in molten condition by the oxidation of the metalloids in the crude iron Without substantially affecting the carbon.

6. The mode herein described of utilizing the calorific power of the metalloids in crude iron in its reduction of iron to the metallic state, said mode consisting in heating the interior of a vessel, then charging this preheated vessel with a uantity of molten crude iron and addin t h quantity of oxi of iron and mechanically agitatin the mixture in a closed vessel and repeate y pouring the molten crude iron through the body of oxid of iron, the quantity o oxid of iron being so proportioned to the quantity of crude iron that the charge is maintained in molten condition by the oxidation of the metalloids in the crude iron without substantially affectin the carbon.

Intestimony whereof l have signed my name to this specification, in two subscribing witnesses.

HENRY D. HIBBARD.

the presence of Witnesses:

O. SEDGWIOK, v EDNA CoLLINs.

mixture, the quaniron being so ereto part at a time a, 

